Passing actionListener method names as arguments to include view

Question

I'm trying to pass action parameters to the partial view in my page but for some reason it says that my parameter is null, even though it's the bean that is being used in the outer page.

Page:

<ui:include src="/templates/common/ajaxConfirmPopup.xhtml">
    <ui:param name="bean" value="#{paginaBean}" />
    <ui:param name="action" value="deleteAll" />
</ui:include>

Calling the action in the partial:

actionListener="#{bean[action]}"

But I get the following exception:

Caused by: javax.el.PropertyNotFoundException: Target Unreachable, identifier 'bean' resolved to null
    at org.apache.el.parser.AstValue.getTarget(AstValue.java:98) [jbossweb-7.0.13.Final.jar:]
    at org.apache.el.parser.AstValue.invoke(AstValue.java:244) [jbossweb-7.0.13.Final.jar:]
    at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278) [jbossweb-7.0.13.Final.jar:]

Am I doing something wrong?

NOTE: Everything works fine when method has ActionEvent parameter, it is not working when method is without parameters.

Turns out that using "action" isntead of "actionListener" made it work, which solves my problem. I don't know why it doesn't work for actionListener though. — Migore, Mar 14 '13 at 20:06
can you check is this working if `deleteAll` method has `ActionEvent` parameter? I think I had this situation sometimes ago and this soled the problem. Like this doesn't work with no-arg methods when bean is passed with `ui:param`. — partlov, Mar 14 '13 at 20:18
Yes, id does! But I have other methods as actionListeners and they work without any parameter. i.e.: The same method work with actionListener (and no parameters) if I don't use a included view. — Migore, Mar 15 '13 at 14:30

score 5 · Accepted Answer · edited Jun 20 '20 at 09:12

This problem is explainable if you have declared actionListener methods in EL 2.2 syntax without any arguments as follows all the time:

actionListener="#{bean.method()}"

which indeed expects an argumentless method. However, the standard JSF way is the following

actionListener="#{bean.method}"

which really expects an ActionEvent argument. Your question history indeed suggests that you were using EL 2.2 syntax all the time and thus you somehow assumed it to be "the standard" while that's not true.

When parameterizing the actionListener method for an include template like as in your approach with actionListener="#{bean[action]}", the actionListener method is been interpreted as

actionListener="#{bean.method}"

which thus expects an ActionEvent argument.

You have basically 3 options to fix this:

Specify the ActionEvent argument in the method, no excuses.
Replace actionListener by action. It's no problem to keep the method void. If e.g. Eclipse EL validation jerks, just tone it in preferences.
Use EL 2.2 syntax like so actionListener="#{bean[action]()}". This however fails in early Tomcat and Glassfish versions.

Passing actionListener method names as arguments to include view

1 Answers1

See also: